Nautilus Questions

Hatchling

I would like to try keeping a Nautilus, in a dedicated tank to themselves.

My question are:

Is a 75gal aquarium big enough?

What kind of decore/Substrate if any?

Filtration?

Last but not least, am I just destining the animal for death? I would not like to do that, is there any possibility for success? I mean past 6months. If that's all it will live, I would rather leave it in the ocean to live a long happy life rather then in my home for a few months.

I suggest reading Don't Fear the Raptor: An Octopus In the Home Aquarium and several other articles. There was a topic about someone having a nautilus in some place here, it passed on in a month or so.
Also read the stuff in the ceph care section and add your tank to the OCTO database.

Titanites

If you plan to get a bimac, you might consider a 50-gallon tank - have a look at the pic under Journals and Photos (Big Ollie). Ollie is in a 46 gallon tank and it is none too large for him. The adult bimacs are a bit bigger than we anticipated.